1. Field of the Invention
The present invention relates to a recording apparatus that is capable of detecting a traveling speed of a feeder belt with high accuracy, and thus capable of recording an image of high quality.
2. Description of Related Art
As a kind of recording apparatus for recording an image on a recording medium, there is known an inkjet recording apparatus that records an image on a recording medium by transporting or feeding the recording medium by circulating an endless feeder belt, and ejecting droplets of ink from a recording portion onto the recording medium as being fed by the feeder belt.
In a recording apparatus such as the inkjet recording apparatus where recording on a recording medium is performed while a feeder belt transports or feeds the recording medium, a traveling speed of the feeder belt (that corresponds to a speed at which the recording medium is fed, which will be referred to as “the feeding speed of the recording medium” or the like) fluctuates, although the traveling speed of the feeder belt is desired to be constant. This results in an inconvenience that the position at which an image is recorded on a recording medium (which will be hereinafter referred to as “recording position”) deviates from a desired position.
Thus, there have been proposed various techniques to control the recording position by detecting a traveling speed of a feeder belt and making an adjustment depending on the detected traveling speed. For instance, JP-A-2004-17505 (see especially paragraphs 0010, 0011, and FIGS. 3 and 4) discloses a method of detecting a traveling speed of a feeder belt, in which one of two opposite edge portions of the feeder belt constitutes a scale portion in which slits are arranged at equal intervals, and an encoder is disposed in order to read the slits to detect the traveling speed of the feeder belt.
However, when the traveling speed of the feeder belt is detected by the technique disclosed in the above-mentioned publication, the feeder belt is bent and stretched at a zone in its circulation path, causing deformation of the slits. When the thus deformed slits are read by an encoder sensor, the obtained traveling speed of the feeder belt is not accurate.
In order to prevent such deformation of the slits, the present applicant has implemented a method such that an endless detection belt less stretchable than a feeder belt and having slits is fixed to the feeder belt at one of opposite edges thereof. However, according to this method, the detection belt does not stretch at a zone where the feeder belt and the detection belt travel together in a bent state, resulting in that the detection belt comes off the feeder belt. Consequently, the slits in the detection belt deform, disabling accurate detection of the traveling speed of the feeder belt, similarly to the above-described conventional method.